It is normal that someone need some time to get used to bifocals for the different focus of the view. Usually the adaptation period
for bifocals takes 10 days. If you have not become comfortable with your bifocal lenses within 10 days, return to your eye doctor for a re-evaluation.
It will take you many days to get used to bifocal prescription glasses. At the beginning, it is normal to get headache while wearing bifocals. So you should wear them for a short time and then increase the amount of time day by day so that you can get used to them very soon.But when you wear bifocals, you should be careful when you go up and down stairs.